This is a solution to a problem not many will have but its worked so well I thought I would write it up. I've just fitted a seven port head with throttle bodies and wanted to remove the servo; because I wanted better pedal feel and didn't want to drill into the throttle bodies for very little vacuum.
The insurance company wanted me to keep the servo and said because it was a factory fit if I removed it there would be a significant increase in the premium and as I didn't want to change insurers I worked out a solution.
I bought a s/h vacuum pump from an Audi A6 part no 8E0927317A
a vacuum reservoir off a VW Passat part no 054129808,
a vacuum sensor switch
a non return valve and some vacuum hose and joints.
I mounted the pump on the r/h front inner wing. You can just about make it out.
I connected a 10mm vacuum hose from the pump to the non return valve, and then carried it up and teed this off to the servo, I carried on from the T into a 10mm to 4mm reducer and teed off to the reservoir and the sensor which I'd mounted on the servo bracket.
The electrics are activated when the ignition comes on. This sends a signal to the sensor and if there is not enough vacuum it switches on the pump through a relay and as soon as the vacuum is generated the sensor switches this off which from empty only takes two to three seconds. In use when I press the brake pedal it uses vacuum from the reservoir to activate the servo and the pump switches on to replenish it.
Because I've used an adjustable sensor I can set the servo up to give as much or as little boost as I want to give me the pedal feel I want.
The sensor has a make and a break circuit on it so I decided to make full use of it. I bought a colour changing led and when the pump is charging the led is red, as soon as the reservoir is full it turns green. This is not necessary, I did it because it was there.
I hope you find this interesting.